Nozzle diaphragm and the like and method of making the same



WADE NOZZLE DIAPHRAGM AND THE LIKE AND METHOD OF MAKING THE SAME FiledJuly 18, 1935 Patented May 4, 1937 UNITED STATES NOZZLE DIAPHRAGM ANDTHE LIKE AND METHOD OF MAKING THE SAME Raymond B. Wade, Swampscott,Mass, assignor to General Electric Company, a corporation of New YorkApplication July 18, 1935, Serial No. 32,001

4 Claims.

The present invention relates to nozzle diaphragms, bucket wheels andlike articles comprising a plurality of partition members or blades heldby and securely fastened to the surface of a. holding member. Theinvention relates more particularly to nozzle diaphragm and bucketwheels used in elastic fluid turbines as a means for directing a streamof elastic fluid and converting available energy from such fluid intomechanical energy. Specifically, the invention relates to the kind ofnozzle diaphragms and like articles in which a plurality of partitionmem- Welding of the thinedge portion is dilflcult and in many cases thethin edge portion near the welding seam is destroyed due to theintensive heat liberated near said edge portion during the weldingprocess. I

One object of my invention is to provide an improved construction ofsuch nozzle diaphragms and bucket wheels, rendering them reliable andemcient in operation.

Another object of my invention is to provide an improvedmethod' ofmanufacturing nozzle diaphragms and like articles whereby they may beproduced at relatively low cost.

For a consideration of what I believe to be novel and my invention,attention is directed to the following description and the claimsappended thereto in connection with the accompan'ying drawing.

In the drawing, Fig. l is a perspective view, partly broken away, of aturbine bucket wheel embodying my invention; Fig. 2 is a spacing memberused in the arrangement of Fig. 1; and Fig. 3 is a sectional view ofFig. 1.

The bucket wheel. shown in the drawing comprises a disk or holdingmember Ill having a rim I l with an outer, cylindrical surface, whichsurface in accordance with my inventionis shaped to define a shoulderl2. From another viewpoint, an outer portion of the rim is removed orcut away to define two coaxial, cylindrical or concentric surfaces l3and IL. The surface I4 is also slightly spaced from the shoulder l2.Spacing means including inner spacers l1 and outer spacers in the formof a band l8 hold the blades in position. The inner spacers H, as shownin perspective in Fig. 2, have a rear portion I9 anda front portion 24.In theconstruction of Fig. 1 the inner spacers I! are slightly radiallyspaced from the surface l3 so that they do not interfere with the roughsurfaces of the welds I6. During manufacture the blades 15 aresuccessively secured to the surface l3 of the rim by means of fusedmetal or welding. Thereafter the inner spacers I1 are insertedintermediate adjacent blades l5 so that the rear portions I9 of thespacers I! contact the surface M. The rear spacer portions l9' then areunited to the rim surface I4 by a weld 20 which may be accomplishedadvantageously by an automatic circular welding machine. When this isdone, the outer ends of the blades I5 are connected together andprevented from relative movement by the provision of the outer spacersiii. The latter in the present. instance form a band or bands with aplurality of openings 2! for receiving the ends of the blades. Theportions of the openings 2| for'receiving the thin edge portions of theblades are somewhat wider than said edge portions. This permitsmanufacture of the band l8 with the openings 2| by a punchingprocess, asis more fully described in the patent to E. D. Dickinson, No. 1,923,264,filed March 25, 1932, and assigned to the same assignee as the presentapplication.

The edge of the band [8 adjacent the thin blade portion has saw-cuts 22.During manufacture the band I8 is secured to the outer ends of thebucket blades or partitions by a. few welds. Thereafter the edgeportions of the band l8 intermediate adjacent saw-cuts are forced orpinched towards the blades to form good contact between the band l8 andthe blades. Finally, the outer ends of the blades are secured to theband 18 by welds 23. It is noted that the welds 23 face away from thepassages defined intermediate adjacent blades or partition means so thatthe rough surfaces of the .welds 23 do not blades or partitions.

In the present instance the openings defined by the inner spacer lladjacent the thin edge portions of the blades are also somewhat widerthan the thickness of thethin blade portions. Therefore, the spacers,having been secured to the rim by the welds 20, are pinched so thattheir front portions 24 (Fig. 2) are forced into contact with theadjacent sides of the blades. This method and arrangement permits theuse of the same spacers IT for different combinations. The frontportions 24 of the inner spacers l1 finally are secured to the surfaceI3 of the rim by a circular weld 25 which also unites the spacer l1 andthe cylindrical surface with the thin edge portions of the blades.

By my invention a smooth passage for the flow of elastic fluid is formedthrough the nozzle passages between adjacent blades, in particular alsoalong the corners defined by the contour of the spacers I! and I8 withthe blades I5. Smoothing of the welds I6 is no longer necessary becausethe outer surface of the welds no longer forms the passages, hence isnot contacted by the fiuid flowing therethrough. It will be readilyunderstood that the smoothing of the welds l6 takes considerable timeand thereby forms an important item in the manufacturing cost of bucketwheels and like articles. Elimination of this expenditure reducesconsiderably the manufacturing cost of such articles.

' surface with a plurality of partitions secured thereto, said methodcomprising the steps of welding the ends of a plurality of partitions tothe cylindrical surface of a holding memberwith one end of eachpartition abutting the surface and thereafter providing a spacerintermediate adjacent partitions in slightly radially spaced relationfrom the surface and providing welds between the cylindrical surface andthe ends of the spacer so that the welds do not form a part of thepassages defined between the partitions 2. The method of manufacturingturbine bucket wheels, diaphragms and like structures comprising thesteps of forming a member with a first cylindricalsurface and a secondcylindrical surface concentrically spaced from the first cylindricalsurface, welding a plurality of partition members to the firstcylindrical surface with one end of each partition member abutting thesurface and thereafter welding a plurality of spacers to the secondcylindrical surface.

- 3. The method of manufacturing turbine bucket wheels, diaphragms andlike structures comprising the steps of forming a member with a firstcylindrical surface and a second cylindrical surface concentrically andaxially spaced from the first cylindrical surface, welding a pluralityof partition members to the first cylindrical surface with one end ofeach partition member abutting the surface, welding thereafter the endof a spacer to the second cylindrical surface intermediate definedintermediate adjacent partition members.

4. An article of manufacture comprising a holding member having twoconcentric axially spaced cylindrical surfaces defining a shoulder between them, a plurality of partitions defining passages, said partitionsabutting the shoulder v and having ends welded to one of the surfaces,

and a spacer between adjacent partitions having end portions secured tothe surfaces, opposite edges of the spacer and adjacent sides of thepartitions forming smooth corners which offer a minimum resistance tothe flow of a fiuid passing through the passages defined betweenadjacent partitions.

RAYMOND B. WADE.

